Tech-Specs
Technical Specifications F r o m t h e M a n u f a c t u r e r of Captek
CAPTEK™
A New Era in Porcelain-Fused-to Metal Esthetics
In today’s world of restorative dentistry, the dentist and technician have
many wonderful materials at their disposal for any given restorative case.
The decision to choose one material over another is based on many things,
including the required esthetic results, quality, strength, cost, and very
importantly, the familiarity and confidence that the dentist and/or the
technician has in the material or technology.
Porcelain-Fused-to-Metal
In spite of a wide variety of available technologies and materials, porcelainfused-to-metal (PFM) is and will remain the primary restoration choice for a
long time to come. The available alloys for PFM have actually changed very
little in the last decade or more, and all fall within one of the five basic alloy
groups:
1.
2.
3.
4.
5.
Gold/Platinum
Gold/Platinum/Palladium
Gold/Palladium
Silver/Palladium
Palladium/Copper (2% gold type)
A Dilemma
It is a well-established fact that a rich gold color is the ideal background for
porcelain. Unfortunately, no alloy has ever been able to achieve both a high
gold color and sufficient strength for use on singles and bridges. The reason
is simple: Palladium and/or platinum are needed for strength and high
temperature stability but rob gold almost entirely of its color leaving a gray
background. Reducing the amount of these metals to maintain color deprives
the alloy of strength and stability. It’s a dilemma that has perplexed
metallurgists since the advent of PFM and still has no solution using “alloy”
technology. Add to this the fact that alloys oxidize, further “darkening” the
background, and it’s no wonder that we have sought out more esthetic
alternatives to PFM. Unfortunately, current alternatives have their own
drawbacks, such as technical sensitivity (especially chair side), strength,
their own esthetic problems, etc.
Captek™
The limitations of alloys led the developers of Captek™ to search for an
alternative way to combine metals without alloying. The process would need
to yield both the necessary physical properties and color for superior
technical and esthetic results.
Captek™ is an acronym for “Capillary Casting Technology”. This
revolutionary material is completely new and has for the first time thrust the
PFM restoration into the class of truly high esthetic restorations (figure 1).
This status has, until now, been enjoyed exclusively by nonmetal-containing
restorations, such as all ceramic and composite resin.
Composite Metal
Captek™ is not an alloy! This also implies that it is not a foil or a sintered
material. It is best described as a composite metal. If you consider a
composite resin to be basically a sea (or matrix) of 97% gold reinforced with
small particles of a very high fusing and high strength platinum
/palladium/gold alloy (approximately 30% of each) (figure 2).
It is important to note that in any composite system, the resulting material
combines the properties of each component individually. In the case of
composite resin, the plastic, curable properties of soft resin are combined
with the high compressive strength, resistance of glass. This forms a third
material that is not only plastic and curable, but also high in compressive
strength, abrasion resistance, and fracture resistance.
In Captek™, the material resulting from the combination of the gold matrix
and the palladium group filler particles possesses the color, biocompatibility,
burnish ability, and nobility of basically pure gold while having the high
temperature stability, strength, and toughness of a high platinum/palladium
alloy. Unlike various 24k gold-plated or cast-ceramic metals, Captek™
actually hardens and strengthens as it is fired during porcelain application.
Advantages
Captek™ has many advantages over anything that has ever been available
(figure 3).
It has physical and esthetic properties that create advantages far beyond what
is possible with traditional PFM crowns.∇Rich gold color. The inner and
outer surfaces present pure 97% gold color, which provides the ideal
background for very natural and vital porcelain esthetics without tissue
“shadowing” caused by the gray color inside traditional cast ceramic alloys.
∇Biocompatibility. Captek™ has exceptional biocompatibility, corrosion
resistance, and resistance to bacterial colonization. Research at Tubingen
University in Germany has shown Captek™ to have higher nobility (lower
reactivity) than pure gold. Similarly, in vivo studies recently completed by
J.Max Goodson,♣Itzhak Shoher,♦and Stephan Imber♥ have shown
bacterial counts (especially gram-negative rods) in the sulcus around
Captek™ crowns with small exposed collars to be up to 1,000% lower than
around natural dentition. The study also showed that porcelain in the sulcus
(all ceramic crowns, porcelain margins, and three point margins)
accumulated up to 800% higher counts than around the Captek™
restorations! ∇No internal, external, or interfacial stresses. No stresses
form between Captek™ and porcelain during firing and cooling. This makes
Captek™ compatible with an extremely wide range of porcelains (basically
all low-and high fusing porcelains on the market today) and is responsible
for extremely high bond strengths with the porcelain, thereby enhancing
vitality and translucency.∇Totally nonoxidizing. Oxides can contaminate
furnaces, create odd color reactions with porcelain, are always dark and can
create a “weak link” at the bonding surface if they are too thick. More
importantly, when present in the furnace, they accumulate on the surface of
the porcelain and actually make it more plaque retentive. Contrary to
popular belief, it has been proven that oxides are not necessary for strong
porcelain bonding-control of stresses is the key to bonding.∇Extremely
small grain size of 15 mm to 20 mm. This allows the margins to be
finished to a very fine edge without loss of integrity. Because there is no
oxide and no gray metal to mask out, the opaque requires only 0.05 mm to
cover! This compares with an average of 0.3mm on cast metal. All this
together allows three-point margins to be created that are virtually
indistinguishable from porcelain margins!
Preparations and Uses
Captek™ requires no special preparation and can be used on any traditional
preparation with featheredge, chamfers, or bevels, to deep shoulders with
porcelain margins. Reduction requirements are the same for Captek™ as for
any traditional PFM preparation. It is not appropriate to incorporate a more
“conservative” preparation for Captek™.
Ideally, because of Captek’s™ impressive bacterial inhibition properties, a
chamfer bevel or shoulder bevel with a subsequently prescribed small metal
collar should be used in all nonesthetic areas (generally from mid-proximal).
There is a tremendous loss of tissue health if 360-degree porcelain or threepoint margins are used where they are not necessary for esthetics! Captek™
can be used for all single anterior or posterior restorations, as well as for
bridges with any configuration of up to two consecutive pontics. It can be
built up to form bands, metal linguals, or occlusal islands, and, in other
words, can accomplish practically anything that can be done with traditional
lost wax-casting techniques.